Hello Paul & Eli,

I have tried again the same thing with a fairly recent Emacs --- built
from a bzr update done yesterday, and it is still the same hanging. 

I need to C-g to exit the hanging up, and I get this in the *Message*
buffer:

-----------------------------------------------------------------------
For information about GNU Emacs and the GNU system, type C-h C-a.
Making completion list...
Generating autoloads for c:/msys/1.0/local/projects/balance/lisp/balance.el...
Quit
-----------------------------------------------------------------------

The load-path variable is the following (for this Emacs started with -Q
so that I get the standard value of load-path):

("c:/Programme/GNU/Emacs/share/emacs/25.0.50/lisp"
"c:/Programme/GNU/Emacs/share/emacs/25.0.50/lisp/vc"
"c:/Programme/GNU/Emacs/share/emacs/25.0.50/lisp/url"
"c:/Programme/GNU/Emacs/share/emacs/25.0.50/lisp/textmodes"
"c:/Programme/GNU/Emacs/share/emacs/25.0.50/lisp/progmodes"
"c:/Programme/GNU/Emacs/share/emacs/25.0.50/lisp/play"
"c:/Programme/GNU/Emacs/share/emacs/25.0.50/lisp/org"
"c:/Programme/GNU/Emacs/share/emacs/25.0.50/lisp/nxml"
"c:/Programme/GNU/Emacs/share/emacs/25.0.50/lisp/net"
"c:/Programme/GNU/Emacs/share/emacs/25.0.50/lisp/mh-e"
"c:/Programme/GNU/Emacs/share/emacs/25.0.50/lisp/mail"
"c:/Programme/GNU/Emacs/share/emacs/25.0.50/lisp/leim"
"c:/Programme/GNU/Emacs/share/emacs/25.0.50/lisp/language"
"c:/Programme/GNU/Emacs/share/emacs/25.0.50/lisp/international"
"c:/Programme/GNU/Emacs/share/emacs/25.0.50/lisp/gnus"
"c:/Programme/GNU/Emacs/share/emacs/25.0.50/lisp/eshell"
"c:/Programme/GNU/Emacs/share/emacs/25.0.50/lisp/erc"
"c:/Programme/GNU/Emacs/share/emacs/25.0.50/lisp/emulation"
"c:/Programme/GNU/Emacs/share/emacs/25.0.50/lisp/emacs-lisp"
"c:/Programme/GNU/Emacs/share/emacs/25.0.50/lisp/cedet"
"c:/Programme/GNU/Emacs/share/emacs/25.0.50/lisp/calendar"
"c:/Programme/GNU/Emacs/share/emacs/25.0.50/lisp/calc"
"c:/Programme/GNU/Emacs/share/emacs/25.0.50/lisp/obsolete")

Here is the output of 'M-x version':

GNU Emacs 25.0.50.3 (i686-pc-mingw32) of 2014-10-25 on CHOUNEK

Also I did again the gbd/attach that Paul had asked for, and it is
attached to this email.

FYI, after trimming balance.el more and more, and checking whether it
hangs up or not, it came out that if balance.el contains a single line
as follows, that is sufficient to cause the hanging forever to happen.

-----------------------------------------------------------------------
(require 'eieio)
-----------------------------------------------------------------------

If under that Emacs I do `C-h f eieio-defclass-autoload', and then from
the *Help* window I follow the eieio-core.el link, I get into the
eieio-core.el bundled with Emacs, aka that in

   c:/Programme/GNU/Emacs/share/emacs/25.0.50/lisp/emacs-lisp/


where my Emacs is installed in:

   c:/Programme/GNU/Emacs


VBR,

  Vincent.